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About Minerals

Biggs Jasper

Biggs jasper is one of the more recently discovered picture rock materials. The first piece was found about 1960 in a creek bottom south of Biggs Junction, Oregon. It is one of the more distinctive jaspers even though it lacks brilliant colors, its design is unique among siliceous rocks. It takes an excellent polish.

Biggs jasper seems to have developed from the muds of short-lived streams that evolved on the surface of a cooled basalt terrain. The raw materials (plastic colloids, silica, clay and iron) came from the weathering of recent igneous rooks and were deposited in the settling basins of stream channels. Heat and pressure from volcanic activity then served to form jasper, small creeping motions led to the marbled rosettes and picture designs.

Biggs jasper is sandwiched between two basalt lava flows that cover Oregon, Washington and parts of Idaho. That plants and animals inhabited the newly formed water courses is shown by the fossil fish found in the area.